Power Inverter

Abstract

A power inverter includes a plurality of power modules; a first casing housing the power modules and a cooling path in which a coolant flows is formed; a plurality of AC busbars connected to AC terminals of the power modules; a holding member, in which a positioning pin protruding to an upper side in a direction opposite to the first casing is formed, that maintains the AC busbars and is fixed to the first casing; a current sensor module including a plurality of current sensors detecting the AC currents of the AC busbars; a frame body for maintaining the current sensors, and a lead terminal protruding from the frame body to the upper side; and a driver circuit board, in which a through-hole used for the lead terminal and a board positioning through-hole are formed, arranged on the upper side of the frame body arranged on the holding member.

1 . A power inverter comprising:
 a plurality of power modules each including a power semiconductor device that converts a DC current into an AC current;   a first casing in which the plurality of power modules are housed, and a cooling path in which a coolant used for cooling the plurality of power modules flows is formed;   a plurality of AC busbars that are respectively connected to AC terminals of the plurality of power modules and are used for outputting AC currents;   a holding member, in which a positioning pin protruding to an upper side in a direction opposite to the first casing is formed, that maintains the plurality of AC busbars and is fixed to the first casing;   a current sensor module that includes a plurality of current sensors detecting the AC currents of the plurality of AC busbars, a frame body, in which a module positioning through hole which the positioning pin is inserted into and is passed through is formed, that integrally maintains the plurality of current sensors and is arranged on the holding member, and a lead terminal being disposed to protrude from the frame body to the upper side and outputting detection signals of the plurality of current sensors; and   a driver circuit board, in which a through hole used for the lead terminal which the lead terminal is inserted into and passed through and a board positioning through hole which the positioning pin is inserted into and passed through are formed, that is arranged on the upper side of the frame body arranged on the holding member and has a circuit, which drives the power semiconductor device based on the detection signals, being mounted,   wherein a tip end of the positioning pin protrudes to the upper side of a tip end of the lead terminal that protrudes from the frame body arranged in the holding member.   
     
     
         2 . The power inverter according to  claim 1 , further comprising a locking portion that is disposed to protrude on the holding member and regulates displacement of the AC busbars in a protruding direction by being passed through a first through hole of each one of the AC busbars and locking a face of the AC busbar that is disposed on a side opposite to a face facing the holding member,
 wherein each of the AC busbars is equipped with a connection portion that is formed in an end portion disposed on a side opposite to an output end and is connected to the AC terminal of the power module and the first through hole that is arranged near the connection portion.   
     
     
         3 . The power inverter according to  claim 2 ,
 wherein the output end side of the plurality of the AC busbars is arranged so as to be passed through the frame body of the current sensor module,   wherein each one of the AC busbars is equipped with a second through hole that is formed on a side closer to the output end than the frame body, and   wherein the holding member is equipped with a protrusion that is inserted into the second through hole.   
     
     
         4 . The power inverter according to  claim 1 , further comprising:
 a capacitor module that is housed in the first casing and is connected in parallel to the plurality of power modules; and   a harness that connects the capacitor module and the driver circuit board to each other,   wherein a guide member that guides the harness to detour around the AC busbars is formed in the holding member.   
     
     
         5 . The power inverter according to  claim 1 , further comprising:
 a top plate portion that is arranged to face a face of the driver circuit board that is disposed on a side opposite to the holding member side; and   a side face portion that is disposed to surround lateral sides of the driver circuit board and is connected to the first casing;   a second casing that houses at least the driver circuit board; and   an insulating sheet, in which a sheet positioning hole which the positioning pin is inserted into and passed through is formed, that is arranged in a gap formed between the top plate portion and the driver circuit board.   
     
     
         6 . The power inverter according to  claim 5 ,
 wherein a convex portion that protrudes in the direction of the driver circuit board and is brought into contact with the insulating sheet is formed in an area facing a heat-generating component mounting area of the driver circuit board in the top plate portion, and   wherein the insulating sheet is interposed between the heat-generating component mounting area of the driver circuit board and the convex portion.   
     
     
         7 . The power inverter according to  claim 6 , wherein a cooling sheet that is firmly fixed to a face of the insulating sheet that faces the heat-generating component mounting area and has thermal conductivity higher than the insulating sheet is interposed between the insulating sheet and the driver circuit board. 
     
     
         8 . The power inverter according to  claim 1 , wherein the holding member is equipped with a plurality of posts that protrude from the holding member in the direction of the driver circuit board and support the driver circuit board. 
     
     
         9 . The power inverter according to  claim 1 , wherein the holding member fixed to the first casing is equipped with a metal base portion that is brought into contact with the first casing and a resin portion that coats a part of the surface of the metal base portion and maintains the plurality of AC busbars.